| 摘要 |
<p>The purpose of the present invention is to promote the atomization of injected fuel by employing the characteristics of the Atkinson cycle. An engine (10) comprises an intake variable valve mechanism (34) and an exhaust variable valve mechanism (36). An ECU (50) executes an exhaust retardation control in cases where the start-up water temperature (thws) is higher than a water temperature determination value (A), i.e., at not-low temperatures where there is leeway in the combustion state. In the exhaust retardation control, valve overlap is increased and blowback on the IVO side is increased by retarding the phase of an exhaust valve (32), while maintaining the increase in the blowback on the IVC side according to the Atkinson cycle. Meanwhile, the ECU (50) executes an intake advancement control instead of the exhaust retardation control in cases where the start-up water temperature (thws) is lower than or equal to the water temperature determination value (A), i.e., at low temperatures where there is no leeway in the combustion state. In the intake advancement control, combustibility is improved by increasing the actual compression ratio and increasing the compression end temperature. Thus, the control can be appropriately switched on the basis of temperature conditions while employing the Atkinson cycle.</p> |
